ASTRO: Adjuvant RT Improves Survival in Elderly Women with Early-Stage Breast Cancer
(ChemotherapyAdvisor) – In healthy, elderly women with early-stage breast cancer, adjuvant radiation should be “strongly considered” as part of their treatment, a study presented at the American Society for Radiation Oncology's (ASTRO's) 54th Annual Meeting, Boston, MA, reported.
“Our study reviewed a large population and found that elderly women with early-stage breast cancer who were treated with adjuvant radiation after surgery had an improvement of their breast cancer survival rate, which suggests that radiation, for appropriate elderly women, should be strongly considered as part of their treatment plan,” said Randi J. Cohen, MD, University of Maryland, Baltimore. “A woman's age alone should not impact whether or not radiation treatment is presented as a viable treatment option.”
The improved outcomes are “likely related to an improvement in locoregional control;” in addition, those selected for radiation “were likely healthier with longer anticipated life expectancy.”
The investigators identified 29,949 women from the Surveillance Epidemiology and End Results (SEER) database between 1990 and 2008 who were ages 70 to 84 years. Each had been diagnosed with clinical stage I, estrogen receptor positive (ER+) breast cancer and had undergone lumpectomy with or without adjuvant radiotherapy and survived at least 1 year following initial diagnosis.
A total of 76% of patients (22,781) received adjuvant radiation treatment. Median survival was 13.1 years for patients treated with surgery and radiation and 11.1 years for patients receiving surgery alone. At 5, 10, and 15 years, OS was 89.5%, 66.8%, and 40.8%, respectively, for those treated with surgery and radiation, vs 83.0%, 56.1%, and 30.2% for those treated with surgery alone. OS was significantly better at all time points for women receiving radiation: at 5 years, OS was 89.5% for those treated with surgery and radiation vs 83.0% for surgery alone; at 10 years, 66.8% vs 56.1%; and at 15 years, 40.8% vs 30.2%, respectively (P<0.05).
Cause-specific survival after 5 years was statistically significant at 98.3% (95% CI 94.9%–95.8%) for adjuvant radiation vs 97.6% (95% CI 97.3%–97.8%) for surgery alone. After 10 years, cause-specific survival was 95.4% (95% CI 94.9%–95.8%) for those receiving adjuvant radiation vs 94.3% (95% CI 93.8%–94.8%) for surgery alone (P<0.05).
Use of radiation therapy was found to decrease as a woman's age increased: 80% of those 70 to 74 years received this treatment, as did 74% of those 75 to 79 years, and 61%, 80 to 84 years.
Previously, a Cancer and Leukemia Group B study of the addition of radiation to lumpectomy and tamoxifen in women ages 70 years and older with clinical stage I, ER+ breast cancer found an absolute reduction of 6% in ipsilateral breast tumor recurrence with the use of radiation at a median follow-up of 10.5 years; however, no improvement in cause-specific survival or OS was observed.
Abstract (Search for Abstract 82)